Rusty crayfish (Orconectes rusticus) are an invasive crayfish species that has invaded many Michigan rivers, streams, ponds and lakes causing a variety of ecological problems including:

• Displacement of native crayfish: rusty crayfish are an aggressive species, frequently driving native crayfish away from their native habitat.
• Consumption of native plants, invertebrates, detritus (decaying plants and animals), fish eggs, and small fish, reducing available food options for native species thus reducing native populations.
• Destruction of aquatic plant beds, limiting habitat for other species and reducing natural erosion control.

For more detailed information about rusty crayfish, please read this article from the Minnesota Sea Grant.

The Perch Lake Owners Association (PLOA) previously worked with the MiCorps Cooperative Lakes Monitoring Program (CLMP) to survey Perch Lake on a regular basis to monitor the presence of rusty crayfish. To date, it does not appear that the rusty crayfish population is at harmful levels.